Microsoft has announced the release of the Windows Phone 7.8 SDK, giving Windows Phone developers the ability to update their apps to be compatible with the new version of the operating system. Windows Phone 7.8 does not support Windows Phone 8 apps, but developers that have written apps for Windows Phone 7.5 can now update those apps with Windows Phone 7.8's new customizable Start Screen features. Apps built for Windows Phone 7.5 mostly run the same on 7.8, but developers can now take advantage of the Windows Phone 8-like small, medium, and large Live Tiles when the app is used on a 7.8 device. The SDK also lets developers test their apps on both low-end devices with 256MB of RAM and higher-end models with 512MB or more of RAM.